Long-term endoscopic management of upper tract urothelial carcinoma: 20-year single-centre experience.	Study Type--Therapy (case series) Level of Evidence 4. What's known on the subject? and What does the study add? Endoscopic management of small, low-grade, non-invasive upper tract urothelial cell carcinoma (UTUC) is a management option for selected groups of patients. However, the long-term survival outcomes of endoscopically-managed UTUC are uncertain because only four institutions have reported outcomes of more than 40 patients beyond 50 months of follow-up. Moreover, there is significant variance in the degree of underlying UTUC pathology verification in some of these reports, which precludes an analysis of disease-specific survival outcomes. The present study represents one of the largest endoscopically managed series of patients with UTUC, with a long-term follow-up. The degree of verification of underlying UTUC pathology is one of the highest, which allows a grade-stratified analysis of different outcomes, including upper-tract recurrence-free survival, intravesical recurrence-free survival, renal unit survival and disease-specific survival. These outcomes provide further evidence suggesting that endoscopic management of highly selected, low-grade UTUC can provide effective oncological control, as well as renal preservation, in experienced centres. OBJECTIVE: • To report the long-term outcomes of patients with upper tract urothelial cell carcinoma (UTUC) who were treated endoscopically (either via ureteroscopic ablation or percutaneous resection) at a single institution over a 20-year period. PATIENTS AND METHODS: • Departmental operation records were reviewed to identify patients who underwent endoscopic management of UTUC as their primary treatment. • Outcomes were obtained via retrospective analysis of notes, electronic records and registry data. • Survival outcomes, including overall survival (OS), UTUC-specific survival (disease-specific survival; DSS), upper-tract recurrence-free survival, intravesical recurrence-free survival, renal unit survival and progression-free survival, were estimated using Kaplan-Meier methods and grade-stratified differences were analyzed using the log-rank test. RESULTS: • Between January 1991 and April 2011, 73 patients underwent endoscopic management of UTUC with a median age at diagnosis of 67.7 years. • All patients underwent ureteroscopy and biopsy-confirmation of pathology was obtained in 81% (n = 59) of the patients. In total, 14% (n = 10) of the patients underwent percutaneous resection. • Median (range; mean) follow-up was 54 (1-223; 62.8) months. • Upper tract recurrence occurred in 68% (n = 50). Eventually, 19% (n = 14) of the patients proceeded to nephroureterectomy. • The estimated OS and DSS were 69.7% and 88.9%, respectively, at 5 years, and 40.3% and 77.4%, respectively, at 10 years. The estimated mean and median OS times were 119 months and 107 months, respectively. The estimated mean DSS time was 190 months. CONCLUSIONS: • The present study represents one of the largest reported series of endoscopically-managed UTUC, with high pathological verification and long-term follow-up. • Upper-tract recurrence is common, which mandates regular ureteroscopic surveillance. • However, in selected patients, this approach has a favourable DSS, with a relatively low nephroureterectomy rate, and therefore provides oncological control and renal preservation in patients more likely to die eventually from other causes.	bladder